The Department of Estuarine and Ocean Sciences will be hosting Brian Yellen on Wednesday, April 2 from 12:30-1:30. Yellen, MA State Geologist and Research Asst. Prof UMass Amherst, will be discussing “The Importance of Sediment to Northeast Salt Marshes and Threats Posed by Regional Decline in Coastal Sediment Supply.” Please join us for this seminar in SMAST East 101-103 or online via Zoom!

 

Abstract:

Coastal environments such as salt marshes, shellfish flats, and beaches depend on a continuous supply of sediment to adjust to rising sea levels. For several years, a UMass Amherst based team has been focusing on assessing (1) the dominant sources of sediment to the New England coast, (2) how sediment contributes to salt marsh accretion, and (3) how humans may be reducing coastal sediment supplies in the Northeast US. In this talk, I will first illustrate the relationship between sediment supply and the ability of salt marshes to build vertically, a process that is essential to maintaining a platform elevation above rising sea levels. Second, I will show how coastal bluff slumping and erosion contributes to coastal sediment supply. We use lidar differencing to quantify the amount of sediment being added directly from bluff erosion. Finally, I will conclude by making use of a newly developed satellite remote sensing tool to demonstrate that coastal suspended sediment has been declining in the Northeast US. Our team hypothesizes that extensive coastal armoring is partly to blame for observed decreases in coastal suspended sediment, potentially posing added adaptation challenges to threatened coastal habitats like salt marshes.